[Intel-gfx] [PATCH] drm/i915: tune down the fast link training vs boot fail

[Ville Syrjälä]

On Tue, Dec 13, 2016 at 08:54:14PM +0100, Daniel Vetter wrote:
> It's been unfixed since a while and no one is immediately working on
> this. And we have the FIXME already. And now also a task in the DP
> team's backlog.
> 
> Cc: Linus Torvalds <torvalds at linux-foundation.org>
> Cc: stable at vger.kernel.org
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> References: https://lists.freedesktop.org/archives/intel-gfx/2016-July/101951.html
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> ---
> Hi Linus,
> 
> Feel free to apply directly in case it annoys too much and you don't
> want to wait for your presents ;-)
> 
> Cheers, Daniel
> ---
>  drivers/gpu/drm/i915/intel_dp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index db75bb924e48..6e875d42642a 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -4014,8 +4014,8 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
>  		return;
>  
>  	/* FIXME: we need to synchronize this sort of stuff with hardware
> -	 * readout */
> -	if (WARN_ON_ONCE(!intel_dp->lane_count))
> +	 * readout. Currently fast link training doesn't work on boot-up. */

s/fast link training/link retraining/ is what I'd put there.

I'm a bit sad to hide it but doesn't look like the proper solution is
going to happen any time soon.

Acked-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

> +	if (!intel_dp->lane_count)
>  		return;
>  
>  	/* if link training is requested we should perform it always */
> -- 
> 2.11.0

-- 
Ville Syrjälä
Intel OTC